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Discussion Starter #1
I bought a 1994 Z28, cheap. squirrels had been living under the hood. every bit of wiring was gone, replaced by these little wire balls. This is a 6 speed car. I had 1 harness for a stick that I've had for many many years, never used because I bought it before I had an LT1 engine.

when I used this harness, everything works put no spark condition

when i use one I purchased from ebay I get a no fuel, and no fuel pip

not sure the year of the one I had, ebay said 1995,,,mycar is a 1994

where to begin??? the ebay harness is current on the engine.
 

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You need to go to the following link and download the 94 & 95 service manuals. You need to compare the 95 engine harness to the original 94 harness. See if there are any different wire hook ups. www.mediafire.com/?40mfgeoe4ctti

Get an obd 1 code scanner. Check for codes as some don't light the cel. Among these code 16 - opti low res signal missing, code 41 & 42- icm problems. These codes will keep fuel injectors from opening, create a no spark condition. Code 16,along with the symptoms for the other codes will cut power to fuel pump.

Another problem that will prevent engine running is a vats security problem. So, when you turn ignition switch to on, does security light come on, then go out after a few seconds? This is normal operation of vats. If light stays on, engine will not run.

Also make sure all the wires of the engine harness are installed in correct place. There are several ground wires on engine that are vital to have a running car.

Finally, check your opti pigtail harness. Take it off and use multimeter set to resistance. Make sure all 4 wires have 0 ohms resistance.
 

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Discussion Starter #3
You need to go to the following link and download the 94 & 95 service manuals. You need to compare the 95 engine harness to the original 94 harness. See if there are any different wire hook ups. www.mediafire.com/?40mfgeoe4ctti

Get an obd 1 code scanner. Check for codes as some don't light the cel. Among these code 16 - opti low res signal missing, code 41 & 42- icm problems. These codes will keep fuel injectors from opening, create a no spark condition. Code 16,along with the symptoms for the other codes will cut power to fuel pump.

Another problem that will prevent engine running is a vats security problem. So, when you turn ignition switch to on, does security light come on, then go out after a few seconds? This is normal operation of vats. If light stays on, engine will not run.

Also make sure all the wires of the ground wires on engine that are vital to have a running car.

Finally, check your opti pigtail harness. Take it off and use multimeter set to resistance. Make sure a
You need to go to the following link and download the 94 & 95 service manuals. You need to compare the 95 engine harness to the original 94 harness. See if there are any different wire hook ups. www.mediafire.com/?40mfgeoe4ctti

Get an obd 1 code scanner. Check for codes as some don't light the cel. Among these code 16 - opti low res signal missing, code 41 & 42- icm problems. These codes will keep fuel injectors from opening, create a no spark condition. Code 16,along with the symptoms for the other codes will cut power to fuel pump.

Another problem that will prevent engine running is a vats security problem. So, when you turn ignition switch to on, does security light come on, then go out after a few seconds? This is normal operation of vats. If light stays on, engine will not run.

Also make sure all the wires of the engine harness are installed in correct place. There are several ground wires on engine that are vital to have a running car.

Finally, check your opti pigtail harness. Take it off and use multimeter set to resistance. Make sure all 4 wires have 0 ohms resistance.
Thank you very much for the link and suggestion, no worries regarding VATS I use C.A.T.S. tuner and remove VATS on everything.

this engine is a fresh rebuild, maybe 30-40 miles on it when I pulled it again (different vehicle).

unfortunately Ground wirecoulsn'y
 

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Discussion Starter #4
Two things.... I've always looked at the 94/95 as basically the same Engine... which is why I'm surprised at the two differences.

second thing... any idea where in that service manual to look for the wiring diagram?
 
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